tcpdump: disable Capsicum if -E option is provided.

The -E is used to provide a secret for decrypting IPsec.
The secret may be provided through command line or as the file.
The problem is that tcpdump doesn't support yet opening files in capability mode
and the file may contain a list of the files to open.

As a workaround, for now, let's just disable capsicum if the -E
the option is provided.

PR:		236819
MFC after:	2 weeks

contrib/tcpdump/tcpdump.c

@@ -2063,7 +2063,8 @@ main(int argc, char **argv)
 	}
 
 #ifdef HAVE_CAPSICUM
-	cansandbox = (VFileName == NULL && zflag == NULL);
+	cansandbox = (VFileName == NULL && zflag == NULL &&
+	    ndo->ndo_espsecret == NULL);
 #ifdef HAVE_CASPER
 	cansandbox = (cansandbox && (ndo->ndo_nflag || capdns != NULL));
 #else